1. Field of the Invention
The present invention relates to a solid electrolytic capacitor equipped with an opening mechanism and more particularly relates to a solid electrolytic capacitor of this type having a fuse on its anode lead terminal side.
2. Description of the Prior Art
Conventionally, solid electrolyte capacitors in which a metal such as tantalum (Ta), niobium (Nb), aluminum or the like for performing a valve action is employed, are widely used in various electronic circuits, and the merit thereof has been known as having a small failure rate. The fault thereof, if it occurs, is often in a mode of a short circuit. When the short circuit happens, a large short-circuit current flows with the result that the capacitor element is heated and sometimes the capacitor element is burnt.
In order to protect other circuit components from this excessive short-circuit current, it is necessary to open the short circuit to cut off the failure mode. To deal with this, a fuse is generally used, and prior arts have been disclosed in Japanese Patent Application Laying-open No.66925/1989, etc. A conventional solid electrolyte capacitor equipped with an opening mechanism stated above has a fundamental structure as shown in FIG. 2. That is, a capacitor element 1 comprises a cathode layer 3 and an anode lead 2, and the cathode layer 3 is connected to a cathode lead terminal 5 with a conductive adhesive 8, whereas a metal piece which is welded to the anode lead 2 is cross-linked to an anode lead terminal 4 by way of a fuse 6. Further, the whole structure other than part of the lead terminals is covered by an encapsulating resin.
In the conventional solid electrolyte capacitor, cross-linkage of the anode lead terminal 4 with the metal piece 10 connected to the anode lead 2 is performed on the same plane by way of the fuse 6, and whereby causing drawbacks as follows:
(1) The metal piece 10 is arranged separately from the anode lead terminal 4, so that the fuse 6 may be broken or other connecting portions may be disconnected by mechanical stress or impacts after the fuse 6 being attached.
(2) The metal piece 10 and the anode lead terminal 4 are arranged on the same plane separately from each other, so that connecting them with the fuse 6 requires a large space, thus making it difficult to increase the capacity of the capacitor element 1 being incorporated in a limited outside dimension.